Re: [RFC PATCH 4/4] doc: commit-graph.adoc: fix up some formatting
Ramsay Jones <ramsay@ramsayjones.plus.com> writes:
> Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
> ---
> Documentation/technical/commit-graph.adoc | 34 +++++++++++------------
> 1 file changed, 16 insertions(+), 18 deletions(-)
Are these the issues?
- Use ={n} prefixes instead of underlines for the section headers. - Use ={n} not #{n} prefixes for the section headers. - A blank line between a leading text before a numbered list.
- Mark-up of displayed materials.
The majority of our pages (I think all of the manual pages) use underlines. Are we getting warnings on them that we'd need to change? I personally find the underlined style easier to read in the source text (even though I understand why people would prefer to use the ={n} prefix style---having to adjust the length of the underline is a bit more work when retitling).
The remainder of this message does not have any comment from me, but is left as a reference for others.
Show 126 quoted lines
> diff --git a/Documentation/technical/commit-graph.adoc b/Documentation/technical/commit-graph.adoc
> index 2c26e95e51..15396f58ab 100644
> --- a/Documentation/technical/commit-graph.adoc
> +++ b/Documentation/technical/commit-graph.adoc
> @@ -1,5 +1,4 @@
> -Git Commit-Graph Design Notes
> -=============================
> += Git Commit-Graph Design Notes
>
> Git walks the commit graph for many reasons, including:
>
> @@ -39,6 +38,7 @@ A consumer may load the following info for a commit from the graph:
> Values 1-4 satisfy the requirements of parse_commit_gently().
>
> There are two definitions of generation number:
> +
> 1. Corrected committer dates (generation number v2)
> 2. Topological levels (generation number v1)
>
> @@ -122,8 +122,7 @@ can be stored in the commit-graph file using the 30 bits available
> to topological levels. This presents another case where a commit can
> have generation number equal to that of a parent.
>
> -Design Details
> ---------------
> +== Design Details
>
> - The commit-graph file is stored in a file named 'commit-graph' in the
> .git/objects/info directory. This could be stored in the info directory
> @@ -149,8 +148,7 @@ Design Details
> helpful for these clones, anyway. The commit-graph will not be read or
> written when shallow commits are present.
>
> -Commit-Graphs Chains
> ---------------------
> +== Commit-Graphs Chains
>
> Typically, repos grow with near-constant velocity (commits per day). Over time,
> the number of commits added by a fetch operation is much smaller than the
> @@ -158,7 +156,7 @@ number of commits in the full history. By creating a "chain" of commit-graphs,
> we enable fast writes of new commit data without rewriting the entire commit
> history -- at least, most of the time.
>
> -## File Layout
> +=== File Layout
>
> A commit-graph chain uses multiple files, and we use a fixed naming convention
> to organize these files. Each commit-graph file has a name
> @@ -170,11 +168,11 @@ hashes for the files in order from "lowest" to "highest".
>
> For example, if the `commit-graph-chain` file contains the lines
>
> -```
> +----
> {hash0}
> {hash1}
> {hash2}
> -```
> +----
>
> then the commit-graph chain looks like the following diagram:
>
> @@ -213,7 +211,7 @@ specifying the hashes of all files in the lower layers. In the above example,
> `graph-{hash1}.graph` contains `{hash0}` while `graph-{hash2}.graph` contains
> `{hash0}` and `{hash1}`.
>
> -## Merging commit-graph files
> +=== Merging commit-graph files
>
> If we only added a new commit-graph file on every write, we would run into a
> linear search problem through many commit-graph files. Instead, we use a merge
> @@ -257,14 +255,14 @@ lock-file. When the file is flushed, we rename it to `graph-{hash3}`
> according to the computed `{hash3}`. Finally, we write the new chain data to
> `commit-graph-chain.lock`:
>
> -```
> +----
> {hash3}
> {hash0}
> -```
> +----
>
> We then close the lock-file.
>
> -## Merge Strategy
> +=== Merge Strategy
>
> When writing a set of commits that do not exist in the commit-graph stack of
> height N, we default to creating a new file at level N + 1. We then decide to
> @@ -289,7 +287,7 @@ The merge strategy values (2 for the size multiple, 64,000 for the maximum
> number of commits) could be extracted into config settings for full
> flexibility.
>
> -## Handling Mixed Generation Number Chains
> +=== Handling Mixed Generation Number Chains
>
> With the introduction of generation number v2 and generation data chunk, the
> following scenario is possible:
> @@ -318,7 +316,7 @@ have corrected commit dates when written by compatible versions of Git. Thus,
> rewriting split commit-graph as a single file (`--split=replace`) creates a
> single layer with corrected commit dates.
>
> -## Deleting graph-{hash} files
> +=== Deleting graph-\{hash\} files
>
> After a new tip file is written, some `graph-{hash}` files may no longer
> be part of a chain. It is important to remove these files from disk, eventually.
> @@ -333,7 +331,7 @@ files whose modified times are older than a given expiry window. This window
> defaults to zero, but can be changed using command-line arguments or a config
> setting.
>
> -## Chains across multiple object directories
> +=== Chains across multiple object directories
>
> In a repo with alternates, we look for the `commit-graph-chain` file starting
> in the local object directory and then in each alternate. The first file that
> @@ -369,8 +367,8 @@ their custom environment:
> access to the new chain until its chain is updated to reference those files.
> (This may change in the future [5].)
>
> -Related Links
> --------------
> +== Related Links
> +
> [0] https://bugs.chromium.org/p/git/issues/detail?id=8
> Chromium work item for: Serialized Commit Graph
Ramsay Jones